Backpack



FIG. 1 is a top, front and right side perspective view of the backpack in accordance with our design.

FIG. 2 is a left side elevational view thereof.

FIG. 3 is a right side elevational view thereof.

FIG. 4 is a bottom plan view thereof.

FIG. 5 is a top plan view thereof.

FIG. 6 is a front elevational view thereof; and,

FIG. 7 is a rear elevational view thereof.

The elements drawn as broken lines show aspects of the backpack and form no part of the claimed design. 

CLAIM The ornamental design for a backpack, as shown and described. 